Craving Fatty Foods? Your Genes Aren't Your Fate

Learn how genetics can influence your diet.

By Carra Richling

Do you crave sugary desserts or prefer the taste of savory, fatty foods? The reason may come down to genetics, according to a study published in the October, 2016 issue of Nature Communications. The study found that people with a mutation of the gene melanocortin-4-receptor (MC4R) had a higher compulsion to eat fatty foods. Researchers found that one in 100 obese people have a defect in the MC4R gene, which leads to weight gain. The good news is your genes are not your fate—changes to your diet and lifestyle will counteract this genetic effect.

Researchers from the University of Cambridge offered volunteers three identical chicken korma dishes that looked and tasted the same, but contained a low, medium and high amount of fat. The study participants were lean and obese, and some had the MC4R gene variant. Those with the gene “exhibited a markedly increased preference for high fat.” They ate almost double the amount of the high-fat chicken compared with the lean volunteers, and 65 percent more than the obese individuals.

In the second part of the study, researchers tested for sugar preference, and used low, medium and high-sugar versions of meringue, whipped cream and strawberries. This time, individuals with the defective MC4R gene ate much less of the dessert with the high-sugar content, compared with the lean and obese volunteers. So, while those with the defective MC4R gene craved fatty foods, they did not crave foods high in sugar.

“Our brains can detect the nutrient content,” says the study’s lead researcher Professor Sadaf Farooqi. “Most of the time we eat foods that are both high in fat and high in sugar. By carefully testing these nutrients separately, and by testing a relatively rare group of people with the defective MC4R gene, we were able to show that specific brain pathways can modulate food preference.” The researchers think the brain evolved that preference for high fat food to survive in the event of famine.

The MC4R Gene and Obesity
The MC4R gene is found on nerves in the brain, and influences what we like to eat and how much of it. The melanocortin 4 receptor is mainly found in the brain’s hypothalamus, the area responsible for controlling our appetite and satiety—that feeling of being “full.” Research finds mutations in that gene account for six to eight percent of obesity cases. A defect in the receptor of the melanocortin 4 disrupts its ability to signal the brain properly, resulting in increased feelings of hunger, decreased satiation and a higher risk of weight gain.

Those with the MC4R gene show significantly better outcomes such as weight loss, compared to those without this gene, when provided intensive lifestyle intervention. The Ornish Lifestyle Medicine Programs is an ideal approach for healthy weight management and reducing obesity-related health risk such as diabetes for those carrying this gene.

Genes Are Not Your Destiny
The good news is that your genes are not your destiny, as Dr. Dean Ornish and his colleagues have discovered in their research. They found lifestyle choices can turn on or off more than 500 genes that are integral to our health. Even for those predisposed to crave fattier foods, lifestyle interventions and eating a predominantly plant-based diet may counter-act gene related influences and risks. In 2007, researchers identified the FTO gene as a “fat mass and obesity associated” gene variant, which is strongly associated with early-onset and severe obesity. Studies have shown both the MC4R gene and the FTO gene do respond better to lifestyle changes and intervention. Many people who carry these genes do not become overweight, proving a healthy diet, exercise, and environment may be just as powerful as our genes.

Looking for other ways to eat more healthily? Reverse heart disease and diabetes, lose weight and reduce your risk of cancer with these tips from Dean Ornish.